3M OHP1820 Overhead Projector, 2600 ANSI lumens, 345 mm, 38 dB, 177.2" (4.5 m), EHJ (24V), 250 W 3M OHP1820 Overhead Projector. Projector brightness: 2600 ANSI lumens. Focal length range: 345 mm. Signal-to-Noise Ratio (SNR): 38 dB. Cable length: 177.2" (4.5 m). Lamp type: EHJ (24V), Bulb power: 250 W